Differential for automobiles



c. BITAT'NER DIFFERENTIAL FR AUTOMOBILES Filed oct. 6, 1926 3 Sheets-Sheet l @Mum/W01,

(atroz/nuits Nov; 8, 1927.

Filed oct. e, 192e 5 Sheets-Sheet 2 Nov. 8, 1927.

C. BITTNER DIFFERENTIAL FOR AUTOMOBILES 5 Sheets-Sheet 5 Filed oct. e, 1926 Patented Nov. 8, 1927.

lnuf'riao STATES CHRISTIAN PATENT OFFICE.

BITTNER, OF ELWOOD, OREGON, ASSIGNOR OF FORTY-NINE ONE-HUN- DREDTHS T HENRY ENDE/ES, OF PARK PLACE, OREGON.

DIFFERENTIAL FOR AUTOMOBILES.

' Application l'ed October 6, 1926. Serial No.v 139,901.

tive size'of certain bevel gears of the dif-'l .ferential'mechanism This allows the employment of tires oflarger size on the rear wheels than on the front wheelsor, if desired, in heavy trucks, the employment of 'wheels of larger diameter, this arrangement ,20 ,facilitating thesteering of v'the vehicle and also decreasing thetire' expense.

Y .A still further' object of my invention is .the provision of a compound differential mechanism so constructed andarranged that y each ofthe four driven wheels of the vehicle may be driven at diferent speeds when the vehicle is rounding a corner being apparent that under suon conditions, none of the `wheels would normally turn at *the 4saine rate of speed, all of them. moving in arcsof circles of differing diameters.

.In carrying out my`V invention, Il employ` a balanced differential mechanism of more v "crless conventional type to which are 0peratively connected two jack shaft sections, each of which'carries an unbalanced differ# ential mechanism which in turn drives two sprocket carrying sleeves, power being A 'transmitted from one of these sprockets to the adjacent rear wheeland fromfthe other of these sprockets tol the adjacent forward wheel. *l i Inpthis connection, a still further object of my invention consists 'inthe provision of a novel form .of lock for the-balanced differential mechanism and of novel forms of locks for the unbalanced dillerential mechanisms, together with means for simultaneously applying or disengaging all of these locks.

A yet further object of my present invention consists in the provision of novel form of differential and transmission -housof course ingfor enclosing the abovebroadly described structure. i'

With these and other objects in view, my

invention will be more fully described, illustrated in the accompanying drawings, and thenspecilically pointed out in the claims -which are'attached to and form a part of this application.

In the dr.. vingsz Figure 1 is a; top plan view ofa conventional. form of motor vehicle running gear, showingmy improved power transmission mechanism in place;

Fig. 2'is' ahorizontal sectional view taken through the diderential mechanism;

Fig. 3 isa fragmentary front elevational i view, upon a. somewhat larger scale, of 'the forward axleA construction;

Fig. 4 isa transverse sectional view taken on the line 4:-4of Fig. 2 illustrating certain details in my unbalanced differential mech-` anlsm. v

Corresponding and like parts are referred to in the following description and indicated in all the views of the drawings by thesaine vreference characters. l.' y

In order to insure a vclear and accurate understanding of my invention and the manner of employing it, I have illustrated its construction in connection with a conventional type of motor vehicle runningv gear including` side frame members 10 and 11 supported inthe customary ,manner above the front and rear axles 12 and 13, both of these axles, in thepresent case,'being 'of the type commonly known as dead axles. Revolvably, inounte'd upon the free ends of the rear axle 13 are therear' drivingwheels 14,- each of which carries a' sprocket wheel 15 by means of which they may be driven.

. The forward axle 12 is preferably upbent somewhat adjacent its ends as shown at 16 and itsends are shaped to provide U-shaped brackets 17 to pivotally receive the spaced arms 18 of steering knuckles 19,'v which form bearings for the spindles of the forward wheels 21. The inner' ends of these spindles are connected by universal joints 22 with the stub drive shafts 23 which are journaled in bearings. formed-in the brackets 17 and in bearings 24 carried by the forward axle proper. Sprocket' wheels 25 are mounted upon these'stub shafts in such a manner that the forward wheels may bedriven by chains trained over these sprockets. At this oint it should be noted that the forward w eels 21, as shown'in thedrawings, are of less diameterthan the rear wheels 14 and must, therefore, be driven at a higher rate of speed when the lvehicle isin motion.

The drive shaft section 26 leads from a clutch 27, of conventional type, through-the forward end of a transmission housing 28, being connected to any suitable form of mul tiple gear transmission containedI in such housing, no such transmission 4being shown as it forms vno part of the present invention. This transmission housing is provided short of its rear end with a transverse wall 29 and the drive shaft section 30 from the transmission mechanism is journaled in a bearing formed 1n this wall, being provided immediately at the rear ofthe l wall with the beveled drive pinion 31.

Broadly speaking, the housing of the di f ferential mechanism, which consists primarily ina central portion 32 and symmetrically formed end portions 33, is secured directly to thefrear end of the transmission housing 28, such end of the housing being extended as shown at 34 to seat in the forward. portion of the intermediate or central housing member 32 and being provided eX- teriorlyand peripherally with a stop fiange 35 against which such portion of the differential housing seats. This central portion of the differential housing includes a main body portion 36 open at its forward end to receive the free end of the transmission hous ing 28 and closed at its rear end by a cap plate 37secured by bolts or other suitable means '38, this cap plate being secured by certain of the bolts directly to the body of the housing and by certain other bolts to reenforci'ng brackets 39 and 40. The ybody portion 36 of the housing is provided at one sidev with an opening 41 and surrounding such opening and interior-ly ofthe housing with an annular iiange 42, the purpose of which will be later explained. At the other side, the body portion of the housing is provided with a somewhat larger' opening 43 and interiorly with an annular surrounding iiange 44 which projects a .considerable distance into the housing.

As the side portionsof the differential housing are identical in. construction, a description of the one willv suffice for both. lEach side portion includes a hollow body 45 provided at one end with a laterally directed flange 46 to receive bolts 47 by means of which itmay be secured to the adjacent side portion of the central housing member, surrounding the opening therein. This body v portion 45 is enlarged at its free end as shown at 48 and'between such enlar ed portion and the main portion is provi ed with a partition wall 49 having a central opening formingabearing 50 provided with lubri# eating channels 5l. The free outer end of this body portion 45 is channeled to receive the laterally directed iiange 52 of a second i body portion 53, bolts 54 being passed'- through'th'is flange and into the body por tion 45 to secure the two together. This body portion 53 is provided intermediate its length with an enlargement 55, the free end of which i's-y provided with an internally threaded opening 56 to receive the thrust cap 57. A bearing plate 58 is* bolted or otherwise securedl across the body portion 53and f providedwith a shaft receiving bore having between the flange 42 and this hub to take up wear and properly support one of' the drivev shaft sections, as will be later explained. .Spaced'discs 67 are interposed between the outer end of the hub portion 64 and the adjacent side of the diiferential housingl and an annular packing ring 68 is clamped between ,these plates to vprevent leakage of oil from one housing section to the other. Secured tothe inner face of the driving gear 63, is a somewhat similarly formed member 69 which, together with thc driving gear, forms, as best shown in Fig..v

2 of the drawings, a cage for the idler pinions 70 of the differential mechanism, these pinions being mounted for free turning movement upon stub shafts 71 carried by the cage and extending inwardly and radi ally thereof, three or more of these openings being provided. The hub portion of loo the member 69 projects into the outer end of the annular flange 44 and a ball race 72 havingball bearings 73 is interposed be,- tween such flange and hub to properly support that end of the differential cage. The beveled gears 74 and 75, which mesh with the pinion's 70, arefenclosed in the cage as is customary and are provided with aligned squared bores 76.

Seated within the space provided by the iiange 44 is a clutch shaft 77, the inner end of which is reciprocally mounted in the hub portion ofthe. member 69 of the difi'er-- `ential cage, 'such end terminating in a ysquared portion 78 which lockingly engages in the squared bore of the beveled gear 74, being so proportioned that when the shaft 77 is moved to innermost position, it will also project into the inner end of the squared bore of the gear 75, to lock the gears 74 and 75'together.` The outer end of this locking shaft 77 is provided with a peripherally grooved head 79 having a concentri-i cally formed squared socket 80.

A vertical shaft 81 is journaled for rotation in the bracket 40, extending through the upper wall of the dierential housing and interiorly of such housing carries a shipper lever in the form of spaced arms 82, the terminals of which engage in the groove of the shaft head as shown at 83,'the flange .44 being slotted for ltheir admission. The outer end of the shaft 81 carries a lever arm 84 by means of which the shaft may be turned to cause reciprocation of the lock'- ing shaft 77 to move it into position to lock the gears 74 and 75 to each other or in position to permit independent movement of such gears.

Y The counter or drive jack of my improved transmission mechanism is formed in two lsections 85 and 86. The inner portion of the section 85 is journaled in the. opening 41 of the differential housing and in the hub por tion 64 of the driving gear 63, said end terminating in a squared extension 87 seating in the f ter portion of the beveled gear 7 5 of the .transmission mechanism 62. The outer end of this shaft section 85 is beveled somewhat to receive lthe inner race member 88 of a bearing race of which the outer race member 89 seats in the thrustcap '57,' (ione bearings 90 being interposed between these" race members.

The shaft section 86 is identical 1n construction with theJ shaft/ member 85, except thatit is shorter, andv -that its inner squared end 91 lseats in the squared socket 80 ofthe locking shaft 77, this socket and squared` terminal being so proportioned` that a portion o'f the s uared 'terminal will, at alltimes, seat in t e socket, irrespective of the position of the locking shaft.`

)InA addition ytothe above T,described-differential mechanism, luy/invention also comrehends the employment of two imbalance differential mechanismsy vlocated one upon either side of the differential previously 'de'` scribed, one being mounted upon the shaft 85 land the other upon the` shaft 86, as will now be explained. As both of these diiferential mechanisms are identical in construction, a description of one will suffice for both; 14a-differential cage, .indicated as a whole bythe numeral 92, is keyed upon each of the shaft sections 85 andr86, said cages being located in the housing 'members 48. Each cage includes a hub portion and' arim portion 93,-connected to the hub portion -by a web 94 formed with radial slots 95. Shafts 96 are journal'ed at their'ends in the rim and hub portions of each cage, ex-

tending radially across the slots of the web portions and each of these shafts carries inner and outer beveled gears 97 and 98,

theformer being one or more teeth larger v 'keyed upon `or Vformed integrally with a sleeve `which extends into the-.enlarged portion 55y of the differential housing to re' and a clamp nut 107. This'latter sleeve is held against outward movement along the shaft by means of a'-` lookin collar 108 threaded upon the shaft section through which the sleeve extends and clampingv discs 109 between it .and the sleeve, a packingring 110 being interposed between these discs. As 'best shown in Fig, 2, ,these sprocket Wheels`106 are considerably larger than the sprocket wheels 101.

Each of lthe differential cages 92 carries a locking plate 111 which is secured to its rim portion and which is provided centrally with a squared opening 112. A locking sleeve 113 is reciprocally mounted about-the sleeve 105, having a key and keyway connection 'therewith as shown at 114 and this sleeve is provided with a squared inner end 115 which, in one position of the sleeve, may

4seat in the squared opening 112 of the lock- 'ceive a sprocket wheel 106 secured by a key ing plate 111. Thesleeve is provided ad- Y ]acent this squared end with a peripheral channel to seat theband 116 of a shipper lever mechanism 1117. This shipper lever isv los carried by a shaft 118 journaled in a Vbracket 119 carried by the differential housing and a lever 120 is keyed upon the outer end of'l this` shaft.

Drive chains 121 are .trained about the' sprockets 25 and 101, while drive chains 122 are`trained about the sprock 15 and 106. the -former'transmitting power to the forward drive shafts, while the 'latter transmit power to the rear wheels.

J ournaled in bearings 123, carried by the side frame members 10 and 11v of the vehicle,

is a shaft 124 having a plurality of upwardly directed lever arms 125, one in alignment "of the llever arms 125 by' a' link 128. Links 129 are pivotally connected to the upper. ends of the other leverarms125 with their rear ends slidably disposed in the free ends of the lever arms 120 and lever arm 84. Nuts, or other fastening devices 130, are secured upon the rear ends of these links 129 and collars 131 are adjustably secured upon the links somewhat in advance of the -lever .arms 120 orthe lever arm 84, as the case may be. Helical springs 132 surround the links between these collars and the adjacent lever arms, washers 133 being preferably interposed 'between the springs and lever arm.

From the foregoing description, it. will be clear -that proper manipulation of the hand.Il

. beveled gear 75 and the other differential mechanism will be locked by the'forcing of the squared terminals of their locking sleeves lameter of such Wheels.

113 into thesquared bores ofthe locking plates 111. The springs 132 permit the hand lever to be swung rearwardly to its full extent, irrespective of Whether the locking members are in proper position to engage each other or not and force co-actinglocking members into locking engagement as soon as they reach such relative position. Upon.

-and formed on the enlarged portions 48 of the body portions 45 to aline with the ears swinging the hand leverin the opposite direction, all or' the dilerential mechanisms are simultaneously' unlocked. i

From the foregoing description, taken in,

connection with the drawings, the operation of my improved transmission mechanism and its dierential mechanisms will be readily understood. lThe central dierential mechanism permits the wheels at one side of the vehicle to revolve at a higher rate of speed than the wheels at the othervv side, when the vehicle is moving in a'fcurve, while the unbalanced diiferentials at either side permit the front and rear wheels to revolve at different rates of speed when going around a curve, this being necessary as it is well known that the front and rear Wheels ol a self-propelled vehicle do not follow the same path except when the car is going in a straight line.l

Furthermore, the dierential mechanisms at the side, because of the two sets of idler beveled gears meshing with drive beveled gears ofditferent diameters, serve to transmit power at different rates of speed to the front and rear wheels, under normal conditions, this compensating for the difference in di-4 This is of great importance as it -permits the use of over-size tires upon the rear wheels without necessitating their employment upon the front wheels, thus reducin'gthe tire expense and also facilitating the steering of the vehicle. Furthermore, Aupon heavy vehicles, such as A' weaves trucks, it is often found to be advantageous to employ relatively small forward wheels and such a dilerential mechanism permits the employment of these wheels in atourwheel kdrive mechanism. i

The locks for the differentials are of considerable importance as in a four-wheel drive of the above type, if any one of the wheels begins to spin Without having {tractive engagement with the road bed, all the other wheels could remain stationary and the vehicle would be stalled.` Under these conditions, the vehicle may be started by locking the differentials when, for the time being,a positive uniform drive will be transmitted to all the wheels. stood that the di erential mechanisms should be unlocked as soon as` the vehicle is again in motion.

Although I have illustrated and described my invention in all its details, it will 0f course be understood that I do not wish to in any way be limited to .such details, as various minor changes, within the scope of the appended claims, maybe made at any time,

without in the slightest degree departingl from the spirit of my invention.

It will of course be under- Formed on the enlarged portions 35v of the D body portions 53 at their forward sides are ears 134 while yat theirl rear sides said body portions are provided with slotted lugs ,135,

134 are ears 136.v Fixed tothe outer ends.

of the shaft members and',86 are brake drums 137, surrounding which are brake bands 138, and adjustable on the lugs 135 arel posts 139 mounting said bands. The bands are provided with lu s 140 which accommoj date .links 141, and )o urnaled through the ears 134 and 136 are brake shafts 142 pro'- vided at their outer ends'with heads 143.

Fixed yto said heads are eccentrically disposed pins 144 .engaged by the links.141..

The shafts 142 carry levers 145'which may be operated in any approved manner for rocking said shafts and tightening the brake straps about the brake drums for applying the brakes and, as will be seen, the restraint of the brakes will be communicated to all four Wheels-of the vehicle.

Having thus described the invention, what is claimed as new is z.

1. In a four wheel drive mechanism,'the i devices for each'dilerential mechanism, links operatively connected to such devices and to a common rock shaft, and a hand lever for actuating such shaft. A

2. In a four Wheel drive mechanism for motor vehicles, the combination with a diferential mechanism, of jack shaft sections operatively connected to the differential mechanism, unbalanced differential mechabers, means for transmitting power from such members to thevwheels of the vehicle, independent means for locking each of the additional differential mechanisms, independent means or locking the ist differential mechanism, each of said means including a lever, links having yielding connections with such levers, and a hand lever for simultaneously moving the links to actuate the levers. v

In testimony whereof I afix my signature.

CHRISTIAN BITTNER, [a 5.] 

